1. Field of the Invention
This invention relates generally to writing instruments capable of counting the number of marking strokes, and pertains more particularly to a ballpoint pen in which the ball of the pen is pressed upwardly in the direction of the housing to activate solar-powered counting and display circuitry, doing so each time a mark is made on a writing medium.
2. Description of the Prior Art
Writing instruments capable of counting the number of marks are not completely new. Examples of such devices are disclosed in U.S. Pat. No. 3,254,836, issued to Claire D. Corpian on June 7, 1966 for "TEACHER'S CORRECTION PEN" and U.S. Pat. No. 3,601,708, issued to Anthony S. Bongiovonni on Nov. 2, 1971 for "MARKER-COUNTER DEVICE." Insofar as we am aware, the alluded to patent devices are capable of performing their intended counting function. However, the pens are quite bulky, cumbersome, relatively costly and sufficiently complex so as to militate against any general use and adoption of such instruments. In order to actuate the mechanical counting mechanisms associated with the two patented devices, the ball point must move through a relatively great distance, for the length of stroke must be sufficient to advance the rotatable number wheels. In addition, the user must apply a sufficient amount of downward pressure so that the mechanical action required to advance the wheels will be realized; this detracts from the ease of making a mark that one normally expects and associates with a conventional ballpoint pen. Owing to the need to house a considerable number of parts, the overall size of the prior art writing implements further detracts from the adoption of such instruments. Hence, as viewed by the applicant, a need remains for a marking instrument that will accurately and conveniently count the number of marking strokes, doing so with an implement that closely resembles a conventional writing device, such as an ordinary ballpoint pen.